Making a bootable backup (hard)disk... how?

Robert Huff roberthuff at
Mon Jun 11 00:15:54 UTC 2012

Ronald F. Guilmette writes:

>  Warren?  Just a couple more quick questions.  You recommend:
>  >>   dump -C16 -b64 -0uanL -h0 -f - /usr | (cd /mnt && restore -ruf -)
>  I'm real curious about you suggestions for the -C and -b values.
>  I have what amounts to a personal workstation.  Yea, OK, it is running
>  mail, web, and FTP servers also, but fundementailly, it is not that busy
>  most of the time.  And it's got 4GB of main installed.  On average, I
>  suspect that I ain't even using half of that.
>  Given all that, why shouldn't I specify (e.g.): -C512 -b1024  ?
>  Wouldn't that all make the dump go faster?

	There are many possible obstacles to faster dump speed;
enumerating them is left as an exercise for the reader.
	As it happens, I have a set-up very similar to what you
describe ... except with 8g of memory.  A few years ago I did some
testing with various cache sizes (as part of diagnosing other
problems) and ended up with C=32.
	(I should probably run the tests again, given some hardware
changes since.)
	That machine's level 0 runs tonight; I will try to remember to
(retain and) post the results.

					Robert Huff

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